Method of producing laminates from mixed thermosetting resin compositions containing polyphenylene ethers

ABSTRACT

THIS SPECIFICATION DISCLOSES THE THERMOSETTING RESIN COMPOSITIONS OF IMPROVED QUALITIES MADE BY COMBINING A HIGH-TEMPERATURE THERMOPLASTIC RESIN, I.E., A POLYPHENYLENE ETHER POLYMER, WITH ORGANIC MATERIALS CONTAINING POLYMERIZABLE CARBON TO CARBON UNSATURATION, PARTICULARLY DIALLYLIC PHTHALATE MONOMERS AND PREPOLYMERS. THESE POLYPHENYLENE ETHER POLYMERS COMBINE WITH POLYMERIZABLE   MATERIALS CONTAINING CARBON TO CARBON UNSATURATION IN THE PRESENCE OF A FREE RADICAL CATALYST. THESE COMPOSITIONS ARE FORMED BY MODERATE HEAT AND PRESSURE INTO ARTICLES WITH EXCELLENT ELECTRICAL AND MECHANICAL PROPERTIES WHICH ARE RETAINED AT ELEVATED TEMPERATURES, AND UNDER CONDITIONS HIGH HUMIDITY.

Aug. 15, 1972 c; L. WRIGH ETAL 3,684,616

METHOD OF PRODUCING LAMINATES FROM MIXED TI-IERMOSETTING` RESINCOMPOSITIONS CONTAINING POLYPHENYLENE ETHERS Original Filed Nov. l5,196'? 4 Sheets-Sheet l FIG. l

POLYPHENY LENE ETHER POLYMER \/V\ AAAAL AAA V VWVVVVVV MONOMERPREPOLYMER LOW PRESSURE Aug. 15, 1972 .1 WRIGHT ETAL 3,684,616

METHOD OF PRODUCING LAMINATES FROM MIXED THERMOSETTING RESINCOMPOSITIONS CONTAINING'POLYPHENYLENE ETHERS Original Filed Nov. 13,1967 4 Sheets-Sheet 5 Aug. 15, 1972- c.L WRIGHT ETAL RESIN COMPOSITIONSCONTAINING POLYPHENYLENE ETHERS 4 Sheets-Sheet 4 Onglnal Filed Nov. 13.1967 IUnited States Patent O1 3,684,616 Patented Aug. 15, 1972 METHOD OFPRODUCING LAMINATES FROM MIXED THERMOSETI'ING RESIN COMPOSI- TIONSCONTAINING POLYPHENYLEN E ETHERS Carl L. Wright, Glen Burnie, and HarryH. Beacham, Severna Park, Md., assignors to FMC Corporation, New York, N.Y.

Original application Nov. 13, 1967, Ser. No. 682,326, now Patent No.3,557,045, dated Jau. 19, 1971. Divided and this application .lune 1,1971, Ser. No. 54,063

Int. Cl. B32b 1 5/ 08; C09j 5/06 U.S. Cl. 156--322 7 Claims ABSTRACT OFTHE DISCLOSURE CROSS REFERENCE TO RELATEDI APPLICATIONS This applicationis a divisional application of U.S. Ser. No. 682,326, tiled Nov. 13,1967, now 1U.S. Pat. No. 3,557,045.

BACKGROUND OF THE INVENTION (A) Field of the invention This invention isconcerned with high performance thermosetting resinous materials thatare useful Where excellent electrical and mechanical characteristics arerequired at normal or elevated temperatures, and under conditions ofhigh humidity. The compositions disclosed are considered to be usefulfor structural parts of high speed aircraft, electrical insulatingcomponents of communications equipment, detecting, control and computingdevices, printing plates and chemical process equipment.

(B) Description of the prior art There is an ever growing need forresinous materials of improved electrical and mechanical qualities,particularly where these qualities must be maintained at elevatedtemperatures or in other adverse environments such as high humidity orchemically corrosive conditions. These high performing plastic materialsare required in structural parts of high speed aircraft, electricalinsulating components of communications, detecting, control andcomputing devices and chemical processing equipment.

Two approaches have been taken inthe development of resinous materialsthat meet high performance requirements: (l) the synthesis of linearpolymer molecules with high melting points-the so-called engineeringthermoplastics, and (2) the production of materials capable of attainingthree-dimensional rigidity through a high degree of chemicalcrosslinking of polymer chains.

High performance thermoplastic materials characteristically are composedof highly ordered, linear chains capable of orientation into veryclosely-packed molecular configurations in which a maximum number ofsecondary valence bond forces can resist the molecular motions ofmelting. Among such materials are the linear polyamides, such as nylons,linear polyesters such as the polycarbonates of bisphenols, thepolyacetals, such as polymethylene oxide, certain isotactic polyolefnsand recently the polyphenylene ether polymers. These materials possesshigh physical strength and toughness qualities or ordinary temperatures.

Thermoplastics are subject to the phenomenon known as creep, or thetendency to distort when subjected to stresses over long periods oftime; also creep increases as the temperature increases. The utility ofthermoplastics under stress is thus limited to temperatures much belowthose at which the materials actually melt or to continuously appliedstresses which are much lower than required for actual rupture.

Fabrication techniques for thermoplastic materials require economicallyfast flow of the plastic, therefore, processing of these hightemperature thermoplastics into molded articles are generally carriedout at temperatures much above the maximum temperatures at which thematerials are useful. Thermoplastics which have useful strengthcharacteristics yat C., for example, are 4generally molded attemperatures in excess of 300 C. High processing or molding temperaturesrequire costly precautions and limit the use of such materials. IAnothershortcoming of thermoplastics is that they all are subject to solvation,either complete or partial, in solvents which, although .specific to 4aparticular plastic, are frequently encountered in commercial use.

Thermosetting resins acquire resistance to melting through the formationof primary covalent intermolecular chemical bonds during curing.Generally the higher the concentration of these intermolecular bonds,commonly called crosslinks, the higher the melting or heat distortiontemperature of the resin. Thermoset resins are typically synthesized asreactive low molecular weight, soluble, thermoplastic polymers or simplemolecules which are converted through chemical action into insoluble,infusible articles during the fabrication process.

The fabrication processes for thermosetting resins, such as molding,laminating or casting, are usually carried out at temperatures below themaximum temperature at which the thermoset material retains usefulstrength characteristics. Because thermoset resin molecules in the curedstate a-re intermolecularly linked by primary valence bonds they arerelatively free of creep phenomena. In general the higher theconcentration of crosslinks the higher the resistance of the cured resinto distortion under stress as the temperature is increased.Thermosetting resins, because they do not creep, retain usefulmechanical strength characteristics at temperatures much closer to theheat distortion temperature than do thermoplastics. Increasing thecrosslinking density increases the heat distortion temperature ofthermoset resins; unfortunately this also increases rigidity whichcauses a loss of shock resistance due to embrittlernent.

Thermosetting resins useful at. elevated temperatures include phenol,urea, and melamine, formaldehyde condensates, unsaturated polyesterresins, epoxy resins and allylic polymers. Each of these thermosettingresins can be formulated to yield a variety of crosslinked densities inthe cured state. These materials have found wide use in the plasticsindustry.

Efforts have been made to obtain improved resinous compositions byblending thermoplastic and thermosettng resins. Other than condensationtype thermosetting resins in combination with thermoplastic resins suchas phenolic resins with polyvinyl butyral resins, blends of the twotypes of resins have generally proved to be incompatible. 'I'hethree-dimensional net-work structures of thermosetting resins normallycannot accommodate more than small quantities of linear thermoplasticresin molecules. Curing the thermosetting resins containing incompatiblethermoplastic resins forces the thermoplastic resin out of thethermosetting structure, resulting in syneresis or blooming on thesurface. Though some measure of apparent compatibility is occasionallyfound, the resultant properties of the combination are poor. Mechanicalproperties are usually much poorer than for either system alone, as thecured resin tends to be cheesy and resistance to distortion under loadis no better than for the thermoplastic resin alone.

SUMMARY OF THE INVENTION We have now discovered thermosetting resincompositions comprising (a) 5 to 95% polymerizable monomer and orprepolymer with carbon to carbon double bond unsaturation, at least 5 ofthe 5 to 95% being a liquid monomer; (b) 95 to 5% of a polyphenyleneether polymer having a repeating structural unit of the formula wherethe oxygen atom of one unit is connected to the benzene nucleus of theadjoining unit, rt is a positive integer and is at least 101, R is amonovalent substituent selected from the group consisting of hydrogen,hydrocarbon radicals free of tertiary a-carbon atoms, halohydrocarbonradicals having at least two carbon atoms between the halogen atom andthe phenol nucleus and being free of a tertiary nt-carbon atom,hydrocarbonoxy radicals being free of a tertiary a-carbon atom andhalohydrocarbonoxy carbon atoms having at least two carbon atoms betweenthe halogen atom and phenol nucleus and being free of tertiarytat-carbon atoms, R and R are both monovalent substituents which are thesame as R and in addition, halogen; and (c) free radical catalyst insucient amount to convert the polymerizable monomer and orresin-polyphenylene ether resin mixture to the thermoset state upon theapplication of heat. Surprisingly, when cured to the thermoset state,these compositions exhibit excellent electrical and mechanicalproperties which are retained at elevated temperatures.

IIt is surprising that these novel compositions containing thermosettingand thermoplastic materials cure into compatible thermoset compositions.Generally the properties both mechanical and electrical fall betweenthose of the thermosetting and thermoplastic components. However, quitesurprisingly, in the thermoset state, preferred compositions comprisingl to 85%, by weight, polyphenylene ether polymer and l to 90% of adiallylic phthalate monomer or prepolymer of which at least 5 of the l5to 90% is monomer exhibit mechanical and electrical properties that arebetter than what might be considered additive improvements due to mixingthe polymer systems. For example, the flexural strength of thecompositions at ambient temperatures are higher than for either polymeralone. This increased flexural strength, coupled with a nearly constantflexural modulus is important, since it denotes greater toughness orless brittleness; that is, the material is both rigid and strong. Forsome preferred compositions these advantages are retained at elevatedtemperatures. A most preferred range of compositions comprises to 35%,by weight, polyphenylene ether polymer, to 75%, by weight, diallylicphthalate prepolymer and l0 to 45% diallylic phthalate monomer.

4 These compositions are strong enough to be used in making printingplates.

We have found that these most preferred compositions in the thermosetstate have better dielectric constants and dissipation factors thanwould be expected from a mixture of the resinous components. Thedielectric constant and dissipation factor over a range of frequenciesare well known, important values, in describing characteristics ofelectrical insulation. These qualities are a measure of the amount ofelectrical energy which is converted into heat by the insulation of analternating current circuit. Diallyl phthalate and diallyl isophthalateare recognized as outstanding thermosetting resins in thesecharacteristics. The thermosetting combinations of allylic resins withpolyphenylene ether polymers proved to be superior to the pure allylicresins alone. Generally the dielectric constant and dissipation factorsfollowed a linear relationship with compositions between pure allylicresin and pure polyphenylene ether polymers. Surprsingly, for these mostpreferred compositions, the dissipation factors were better than couldbe calculated from values of the pure resin systems.

We have also found that certain other most preferred thermosettingcompositions exhibit unusually good electrical characteristics, whichproperties are retained after prolonged exposure to adverseenvironments, such as elevated temperatures and high humidity.Compositions containing 55 to 85% polyphenylene ether polymers, 0 to 30%diallylic phthalate prepolymer and l5 to 45% diallylic phthalate monomerexhibit flexural strengths at ambient temperatures in the range of14,500 t0 20,000 p.s.i. or in excess of either the thermosetting orthermoplastic resin alone. Dielectric constants are in the range of only2.7 to 3.0 and dissipation factors are less than .006% over a range offrequencies. This combination of high mechanical strength and lowdielectric constant and dissipation factor, both of which qualities aremaintained at elevated temperatures and in the presence of water, isapparently unique among rigid thermoset resins.

The physical form of these novel compositions, in the uncured state atroom temperature, varies from liquid slurries to dry powders. Because ofthe varied physical forms available, a variety of curing conditions areused, depending on the pressure required to form the system at thefusion point. Quite surprisingly, all the conventional moldingtechniques for allylic resins may be used for the compositions of thisinvention including casting of the very liquid systems, vacuum-bagmolding at l5 p.s.i. absolute, autoclave molding at 50-300 p.s.i.,matched metal molding at -500 p.s.i., and high-pressure compression andtransfer molding at 50G-10,000 p.s.i. Even compositions high inpolyphenylene ether resins can be molded under relatively mildconditions.

These novel compositions can be used in preparing laminates either bythe lwet lay-up or prepreg techniques. These novel compositions are alsoused with solvents in preparing coatings and insulating varnishes. Thecompositions can be compounded with or without llers and reinforcingmaterials in molding and casting useful articles.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a triangular graphillustrating the unfilled molding compositions of this invention. Thisfigure also illustrates some compositions which are excluded from thisinvention. Area I is excluded from the invention because moldingpressures in excess of about 10,000 pounds are required; and Area II isexcluded because the compositions are not significantly differentproperty-wise from mixtures of monomers and diallylic phthalateprepolymers. Areas III, IV and V; of FIG. l, include the compositions ofthis invention.

FIG. 2 is a triangular graph illustrating the most preferredcompositions of this invention. Compositions of Area A are most usefulin combination with fillers and reinforcing agents. Compositions of AreaB are most useful when essentially untilled.

FIG. 3 is a graph illustrating the unexpected improvement in exuralstrength at ambient temperatures of compositions of this invention overwhat would be expected from additive properties of polyphenylene etherpolymers and mixtures of diallylic phthalate monomers and theirprepolymers.

FIG. 4 is a graph illustrating the unexpected improvement in flexuralstrength at elevated temperatures of preferred compositions of thisinvention over what would be expected from additive properties ofpolyphenylene ether polymers and mixtures of diallylic phthalatemonomers and their prepolymers.

DESCRIPTION `Ol?" THE INVENTION AND THE PREFERRED EMBODIMENTS All of thepolyphenylene ether polymers currently available have been found to beuseful in practicing this invention. One method of producingpolyphenylene ether polymers is described in U.S. Pat. 3,306,875 issuedFeb. 28, 1967. We have used three polyphenylene ether polymers availablefrom the General Electric Company, Noryl and grades 631-101 and 631-111,and found them all to be useful in practicing our invention. As far aswe know all the polyphenylene ether polymers known in the art are usefulin practicing this invention.

Materials containing polymerizable carbon to carbon unsaturation usefulin practicing this invention include reactive-type polyester resins,reactive monomers, and allylic prepolymers. Monomers useful inpracticing this invention include diallyl orthophthalate, diallylisophthalate, diallyl chlorendate, methylmethacrylate, styrene anddivinylbenzene.

Allylic prepolymers, unsaturated polyester resins and polydienes may beincorporated in the compositions of this invention where desired. Theamount of these polymers varies between about and 90%, by weight, of thetotal composition. Diallyl phthalate, diallyl isophthalate, and diallylchlorendate prepolymers unsaturated polyester resins, and polybutadieneare useful resins in practicing this aspect of the invention.

The polymerizable materials must contain carbon to carbon unsaturationand can be solid materials such as allylic prepolymers. The solidpolymerizable materials can comprise up to 90% by weight of the totalpolymer composition. Liquid polymenzable materials containing carbon tocarbon double bond unsaturation, generally monomers or combinations ofmonomers with unsaturated polymers are important in these novelcompositions. The ratio of polymerizable materials to polyphenyleneether polymer should lie between 5:95 and 95:5. An unsaturated polymerimparts better viscosity and handling characteristics to the compositionthan does a polymerizable monomer. However, at least 5 of the 5 to 95%polymerizable material must be monomer.

The diallylic phthalate prepolymers, diallyl orthophthalate and diallylisophthalate, used in this invention are manufactured in a conventionalfashion by polymerizing a monomeric material to produce a solution ofthe soluble preploymer in monomer, to a point short of gelation, whichoccurs when the molecular weight of the prepolymer reaches a point whereit becomes insoluble in the monomer. These prepolymer-monomer solutions(called dopes) are then separated into a solvent soluble preploymerfraction, and monomer. This may be done by treatment with a solventwhich dissolves the monomer while precipitating the prepolymer, or byother means which will leave a soluble prepolymer substantially free ofmonomer. A typical method of separating such polymers is described byWillard in U.S. Pat. 3,030,341, issued Apr. 17, 1962. These prepolymersare solids containing little or no monomer; they can be storedindefinitely in this form, since they require a catalyst and either heator actinic light to convert them to the insoluble stage.

We have found that in addition to allylic prepolymers the gel polymersof allylic monomers such as are described in U.S. patent applicationsSer. No. 637,320, tiled Apr. 20, 1967, and Ser. No. 554,669, iledl .lune2, 1966, can also be used in practicing this invention.

The novel compositions of this invention employ a free radical catalystin sufficient amount to convert the polymerizable monomer and/orresin-polyphenylene ether resin mixture to the thermoset state upon theapplication of heat. Peroxide catalysts which promote the interactionbetween the unsaturated monomer and/or resin containing carbon to carbonunsaturation does not have to exclude homopolymerization, but must be acatalyst that does not yield only homopolymers. We have found catalystswhich have a ten hour half-life in benzene at a temperature in excess ofC. should be used to some extent to catalyze the reaction of thisinvention. Mixed catalysts may be used, but at least part of thecatalyst must be a catalyst having a ten hour half-life at a temperaturein excess of 110 C. in benzene. We have successfully used dicumylperoxide, tertiary butyl perbenzoate and2,5-dimethyl2,5di(tert-butylperoxy) hexyne-3 alone or in combinationwith benzoyl peroxide. We have found dicumyl peroxide gives the bestresults in laminates and tertiary butyl perbenzoate the best results inmolding compositions where the compositions contain allylic monomers orprepolymers. In any event the catalysts well known in the art to promotethe cure of allylic compositions are generally useful in practicing thisinvention.

The molding compositions of this invention may be pre-mixed, powdered,granular or dough type. The molding compositions are prepared inconventional equipment well known in the plastics industry to be usefulin compounding diallyl phthalate, epoxy and polyester molding compounds.The molding compositions may be filled or unlled. The polyphenyleneether resin, polymerizable monomer and or prepolymer, free radicalcatalyst, internal mold release, pigment, inhibitor, etc. are simplymixed together in a heavy duty mixer. The mixing may be done with orwithout the use of solvents. However, if solvents are used they shouldbe removed from the premixed compound before molding. The moldingcompositions can be molded under conditions normally used for allylicmolding compositions, i.e., they are molded at from about to 180 C. forabout 1 to 60 minutes. Because of the varied viscosities of these novelmolding compositions the molding pressure can vary from about zero (0)to 10,000 p.s.i. depending on the composition.

A wide variety of water insoluble, inert inorganic fillers may be usedin these molding compositions. Fillers which can be used in practicingthis invention include calcium carbonate, both precipitated and wetground types, calcium silicate, ground silica, calcined clays, chalk,limestone, calcium sulfate (anhydrous), barium sulfate, asbestos, glass(powdered), quartz, aluminum trihydrate, aluminum oxide, antimony oxide,inert iron oxides, and ground stone such as granite, basalt, marble,limestone, sandstone, phosphate rock, travertine, onyx and bauxite.Additionally, inert librous materials may be used such as syntheticfibers, glass fibers, asbestos and cellulosic fibers. Up to 200 parts byweight of iiller and or ber per 100 parts by weight of diallylicphthalate-polyphenylene ether resin may be used in these moldingcompositions.

A series of molding compositions, representative of this invention, wasprepared by yblending polyphenylene ether polymers in a powdered formwith varying amounts of diallyl orthophthalate monomer and prepolymer towhich was also added 2 parts of dicumyl peroxide, by weight, per 100parts of polyphenylene oxide resin plus diallyl phthalate monomer andprepolymer. A similar series of molding compositions was prepared usingdiallyl isophthalate monomer and prepolymer.

The novel resin compositions of this invention are readily used inpreparing glass reinforced laminates by either the wet lay-up o1 prepregtechniques. Wet lay-ups are prepared by making a liquid blend of apolymerizable liquid, i.e., a monomer such as diallyl orthophthalate,polyphenylene ether polymer, catalyst and where desired an allylicprepolymer or reactive polyester, and other modifying ingredients suchas dye, pigment, fillers, inhibitors, glass coupling agents and soforth, which is poured onto one or more layers of a fibrous non-wovenglass mat or Woven glass fabric, which has preferably been treated witha glass coupling agent, to impregnate the reinforcing glass; afterimpregnation the product is laminated under heat and mild pressuresaccording t procedures well known in the art to be useful for curingallylic resin laminates.

A typical slow cure is effected by placing the wet layup in a vacuum bagand applying a vacuum of 28 to 29.5 inches of mercury for about 5 hoursto remove bubbles; the evacuated lay-up is then pressed at 30 to 50p.s.i. for 30 minutes at 82 C., 60 minutes at 104 C., 30 minutes at1411C., 15 minutes at 149 C., and then cured an additional 60 minutes at149 C. in a laminating press under contact pressure. Thin sections canbe cured more rapidly; for example 30 to 50 p.s.i. for 60 minutes at 149C. The amount of glass in the lay-up can be as high as 80% and thepreferred amount of reinforcing glass is 50 to 75%.

The novel resin compositions of this invention can be employed in theusual process for manufacture of fibrous reinforced thermoset resinlaminates using the prepreg technique. The polymerizable liquid, i.e.,monomer such as diallyl orthophthalate and the like, polyphenylene etherpolymer, catalyst and where desired an allylic prepolymer and modifyingingredients such as dyes, pigments, iillers, glass coupling agents,inhibitors and so forth are mixed together and used to impregnate afibrous non-Woven mat or a woven fabric; where glass mats or fabrics areused it may be desirable to have the glass treated with a glass couplingagent. The use of some solvent is usually required in order to reducethe viscosity level of the resin composition to make it suitable forapplication to the mat or fabric with conventional commercial saturatingor impregnating equipment.

In the compositions of this invention it is not necessary to dissolvethe polyphenylene ether resin. Simple uniform dispersion of thepolyphenylene ether resin powder in the solvent-monomer-polymerizableresin mixtures suices. Prepregs are generally most economicallyprocessed with 30 to 60 parts of the resin composition dispersed in 70to 40 parts of a suitable solvent such as acetone, methy1 ethyl ketone,methyl isobutyl ketone, toluene, xylene, chloroform, methylene chloride,trichloroethylene, perchloroethylene and mixtures thereof and othersolvents known in the trade to be useful in preparing allylic prepregs.

The mat or fabric is impregnated with the solvent solution and thendried to remove the solvent. After impregnation and drying of theimpregnated fabric the laminate is laid up and cured with heat and mildpressure using cure cycles and conditions similar to those used incuring the wet lay-up type laminates. Roving, including glass roving, issimilarly pre-impregnated for processing by filament winding techniquesinto pipe, other cylindrical shapes and hollow tapered and conicalshapes. Products made by filament winding are generally cured at about150 C. `in 60 minutes. The liber content of the prepreg laminates variesfrom about to about 40% by weight for low density libers and up to about55 to 75% of the total weight of the cured laminate for glass mat orglass fabric laminates. The fiber content of filament Woundconstructions such as pipe, when made from impregnated glass roving, isgenerally about 70 to 80% of the total weight of the cured product.

Reinforced laminates of fibrous materials much as glass cloth, glassmats, synthetic liber, cloth mats, paper and the like can be copper-cladto produce copper-clad laminates with excellent electrical properties tobe used in preparing printed circuits and the like. The copper-cladlaminates are prepared by coating copper foil with a polyphenylene etherresin coating and then baking the coated copper foil at 160 C. for aboutl5 minutes. The baked resin coated foil is then placed on resinimpregnated fibrous materials such as glass cloth which has beenimpregnated with the novel resin compositions of this invention whichcontain at least about 10% or more polyphenylene ether resin and thenthe laminate is pressed at 50 to 2,000 p.s.i. at 100 to 170 C. for atleast 5 minutes to convert the resinous materials to the thermosetstate. As indicated above dicurnyl peroxide is the preferred catalystfor producing the copper-clad laminates of this invention. The resultingcopper-clad laminate has excellent adhesion of the copper to the basematerial which has excellent electrical properties. Quite surprisinglywhen tested according to NEMA Standards Publication LLI-1966, but at upto 200 C. rather than the 25 C. standard, these copper-clad laminatesretained essentially all of their electrical properties as measured atroom temperature.

Compositions containing a polyphenylene ether polymer, a polymerizableliquid, such as allylic monomer, and allylic prepolymer were found to bevery useful in practicing this invention. Where allylic prepolymers andallylic monomers are used it was found to be very useful to use anallylic composition which results from the polymerization of the monomerto produce prepolymer in solution in the monomer. However, prepolymermay be simply dissolved in the monomer and used in the compositions ofthis invention. In the first alternative about 25% by weight ofprepolymer in monomer represents about the maximum amount of prepolymerin monomer that can be obtained without gelling the prepolymer-monomersolution. In these compositions the ratio of monomer plus prepolymer topolyphenylene ether resin should be between 5 :95 and 95:5. Using the 25by weight prepolymer in monomer solutions, often referred to as dope, wevaried the ratio of polyphenylene ether resin from 10:75 while varyingthe ratio of dope from :25. These compositions were moldable, and couldbe dissolved or dispersed in a solvent and used for preparing glasslaminates by the prepreg technique. Similar diallyl isophthalatepolymer-diallyl isophthalate monomer mixtures were used in moldingcompounds and prepreg laminates With similar results.

The compositions of this invention can be dissolved in suitable solventsto form coating solutions. These solutions may be applied to substratessuch as metal, plastics and wood; dried and cured at about 300 F. togive clear surface films with excellent adhesion, toughness and highheat and chemical resistance.

Solutions of polyphenylene ether resin, a variety known as Noryl(registered trademark of General Electric Company), and diallylisophthalate prepolymer, and dicumyl peroxide catalyst when dissolved intrichlorethylene were found to separate into two layers in which thebottom layer was clear and straw colored and the top layer was nearlyopaque. Infra-red analysis showed polyphenylene ether resin and diallylisophthalate prepolymer to be present in both layers suggesting thatseparation was simply between soluble and more or less insolublefractions of polyphenylene ether resin. The bottom layer when dried gavea tacky, clear iilm which could be cured at 300 F. to a tough adheringfilm. This bottom clear solution was also ideally suited for saturatingsupporting materials such as glass fabric or glass mats for producinglow pressure laminates. The top layer when dried gave a rubbery blacksolid which could be transferred and compression molded at pressures of1,000 to 3,000 p.s.i. at 300 F. to yield hard glossy moldings.

The test methods appearing in the following list were followed intesting the molded specimen made from the various compositions disclosedin the examples.

9 (A) Flexural strength 1ASTM D-790 (B) Modulus of elasticity-ASTM D-790(C) Tensile strength-ASTM D638 (D) Izod impact- ASTM D-2516 (E)Compressive strength-ASTM D-695 (F) Deflection temperature-ASTM D-64-8TABLE L--MOLDED DIALLYL PHTHALATE-IOLYPHENYLENE ETHER POLYMERCOMPOSITIONS Comparison example Diallyl orthophthalate:

Prepolymer 47.5 45 42.5 40 35 Monomer 47. 45 42. 5 40 35 Polyphenyleneether polymen--- 5 10 15 20 30 Dicumyl peroxide 2 2 2 2 2 HardnessRockwell M 114 113 112 110 10G Izod impact, rt.1b./in 2. 42 2. 01 2. 352. 39 2. 02 Flexural strength, p.s.i.' 5 C at 1156 at et 0 C- 4, 5Flexural modulus, 105 p.s.

C 5. 2g 5. 4.71 150 C- 1. 2 1. .26 Tensile strength, p.s. 3, 840 2,9204, 900 4,180 4,620 Water absorption, percent.. +0.45 +0.43 -I- .39 .44-l- .39 speinc gravity 1. 266 1. 757 1. 247 1. 233 1. 215

.e107/1.180 .50o/1.138 .482/1007 405/.972 462/.817 .G70/1.201 0.4/0.9.654/1207 .60o/1.119? .579/1ig02 .554/1832 46a/.881 .754/1414 6 m 0.101.. .4 1 .2 10.4 s. 11 s Surface resistivity (X1015 ohm) 5. 86 9. 37 11.7 8.27 8. 27 5. 41 10 (G) Water absorption--ASTM D-570(a) EXAMPLE 2 (l)DSPclc. gralStyIAT/SIODJ A series of molding compositions were preparedand (I) Die ctrtlc'"f t 'STM D 150 molded as described in Example l, butsubstituting di- (K)) Sima 10u dac t. .t- ASTM D 257 allyl isophthalatemonomer and diallyl isophthalate pre- L) Florme alt il; aclsrllg polymerfor the corresponding diallyl orthophthalate a e res s a E monomer andprepolyrner of Example 1. The details of (M) Hardness- ASTM D-785 themolding compositions and physical and electrical properties of moldedsamples are set forth in Table Il.

TABLE II.MOLDED DIALLYL PHTHALATE-POLYPHENYLENE ETHER POLYMERCOMPOSITIONS Comparison example Diallyl isophthalate:

Prepolymer 47. 5 45 42. 5 40 35 50 Monomer 47. 5 45 42. 5 40 35 50Polyphenylene ether polymer-. 5 10 15 20 30 0 100 Dieumyl peroxide 2 2 22 2 2 Hardness Rockwell M. 110 113 112 111 110 118 Izod impact,it.lb./in 1. 28 1. 98 1. 311 1. 64 2. 61 1. 09 Flexural strength, p.s.i.

4. 88 4. 67 4. 72 4. 57 4. 47 4. 90 3. 6 2. l5 1. 85 1. 63 1. 60 1.61 2.44 2. 5 Tensile strength, p. 2, 400 3, 510 4, 120 3, 930 3, 630 2, 08011, 000 Water absorption, percent-. +0. 49 +0. 41 -l-O. 38 +0. 41 .43+0. 51 +0. 11 Specific gravity 1. 253 1. 246 1. 230 1. 228 l. 212 1. 265Dielectric constant 10S/106 780/1. 011 811/. 951 794/. 885 722/. 855735]. 767 998/1. 053 0. 4/0. l 733/1. 074 851/ 1. 028 784/. 971 721/1.018 6580/. 809 850/1. 099 9. 92 9. i 9. 78 9. 74 l2. 0 10. 7 80 9. 37 .87. 03 6. 39 7. 03 7.81 10 The followmg examples, illustrating the novelproducts EXAMPLE 3 disclosed herein, are given without any intentionthat the invention be limited thereto. All parts and percentages are byweight.

EXAMPLE 1 Molding compositions were prepared by stirring togethercombinations of powdered polyphenylene ether polymer (polyphenyleneether polymer--Type 631-111, General Electric Company) in varyingamounts With mixtures of diallyl orthophthalate monomer and diallyl 1Thellexural strengths at 150 C. for the unfilled resin systems wereobtained after 1/1 hour conditioning at 150 C. Each individual specimenwas held to 1/2 hour conditioning to avoid any ambiguity that may becaused by post-curing in the test oven. Only maximum exural yield wasmeasured.

The compositions, molding conditions and physical propJ erties of moldedsamples are set forth in Table Ill.

TAB LE IIL-MOLDED DIALLYL PHTHALATE-POLYPHENYLENE ETHE R POLYMERCOMPOSITIONS Polyphenylene ether polymer-- 20 40 50 75 Diallylorthophthalate polymer mixture 80 60 50 25 Dicumyl per 2 2 2 2 Curingconditions at 5 Pressure, p.s.i- 100 300 700 3, 000 Time, minutes 30 3030 7 Flexural str., p.s.i. at-

ry 3.31/3. 24 3. 22/3. 18 3. 12/3. 07 2.92/2. 88 Wet 3. 38/3. 30 3.Z5/3. 21 3. 13/3. 00 2. 96/2, 88 D.F. 103/105:

Dry, percent 0. 527/0. 000 504/. 018 511/. 536 383/. 271 Wet, percent 0.575/1. 081 472/. 784 505/. 576 282/. 287 Volume resistivity, ohm-om8.82Xl5 2.4X1015 1.2)(1013 2. 7 1015 Surface resistivity, ohm- 1.00X1055. 0 10l5 6.4)(10l5 0.9 101G Water absorption, percent +0. 41 31 +0.15Specific gravity 1. 237 1. 183 1. 191 1. 134 Izod, ft.1bs 1. 84 1. 984.85 2. 12 Rockwell M 111 103 105 98 EXAMPLE 4 Diallyl isophthalatemonomer was polymerized at 120 C. using a combination of 0.1% tertiarybutyl perbenzoate and 0.2% hydrogen peroxide as a catalyst until 25% ofthe monomer had been converted to diallyl isophthalate prepolymer. Theresultant diallyl isophthalate prepolymermonomer solution was used inmaking blends with polyphenylene ether polymers as in Example 2 andwhich were catalyzed with the 2% dicumyl peroxide per 100 parts ofresins and monomer. Test specimens were molded from all compositions.The compositions, molding conditions and physical properties of moldedsamples are set forth in Table IV.

TABLE IV.-MOLDED DIAL'LYL ISOPHTHALATE-POLY- PHENYLENE ETHER POLYMERCOMPOlSLTIONS Polyphenylene ether polymer 50 75 Diallyl isophthalatepolymerization mixture 80 50 25 Dicumyl peroxide 2 2 2 Physicalappearance of blend Liquid Paste Dry Curing conditions at 155 C.:

Pressure, p.s.i 200 200 5, 000 Time, minutes 30 30 5 Izod impact, it.1bs2. 20 2. 61 2. 51 Rockwell M 110 102 96 Flexural str., p.s.i. at

C 14,260 17,830 17,880 150 C 2, 160 405 60 Flexural modulus, p.s. a

25 C 4 18)(105 3.69)(105 3 39Xl05 150 C 4 35)(10* 9. 75X103 Waterabsorption, percen +0. 38 4 0.27 +0.15 Specific gravity 1. 229 1. 170 1.136

D 3.16/3.08 3. 06/2. 00 2. 89/2. 83 Wet 3.21/3. 12 3.07/3. 00 2. 91/2.86 D F. 103/1 Dry, percent- 0. 904/0. 916 0. 502/0. 555 613/. 344 Wet,percent-- 0. 900/0. 961 0. 646/0. 590 608/. 372 Volume resistivity, ohm-9. 15)(1015 4. 27)(105 1. 93 101u Surface resistivity, ohm 6. 70X1015 4.69 101b 7. 03x10l EXAMPLE 5 A glass cloth laminate was prepared asfollows: A mixture of 500 parts of polyphenylene ether polymer(polyphenylene ether polymer-Type 631-111, General Electric Company) and500 parts of diallyl isophthalate prepolymer were ball milled togetherovernight to facilitate dispersion of part of the mixture in thefollowing saturating solution: Three hundred parts of the ball milledmix ture were added to a solution containing 400 parts of diallylisophthalate prepolymer, 300 parts of diallyl isophthalate monomer,parts of dicumyl peroxide catalyst, 10 parts of gammamethacryloxypropyl-trimethoxysilane and 1700 parts of acetone, withvigorous agitation of 30 minutes. Woven glass cloth was impregnated withthis dispersion and allowed to dry at least 40 hours in air at roomtemperature. The dried glass cloth, Type 181, prepregs were cut into 12"x 12 squares and stacked 13 plies deep With the Warp yarns parallel. Theprepreg lay-up was laminated in a flat ybed press for 30 minutes at 80C. at contact pressure, 30 minutes at 120 C. at 300 p.s.i., and 1 hourat 160 C. at 3010 p.s.i. A comparison example was made using a prepregsolution containing 800 parts of diallyl phthalate prepolymer, 200 partsof diallyl isophthalate prepolymer and 20 parts of dicumyl peroxidecatalyst. The comparison laminate was cured as above. The laminatescontaining the polyphenylene ether polymers were noted to be nearlytransparent while the control sample was quite translucent andnoticeably crazed. The physical properties of the 2 laminates are setforth in Table V.

TABLE V.-GLASS CLOTH LAMINATES Diallyl isophthalatepolyphenylene etherpolymer Comparison laminate 5-1 laminate Flexural str., p.s.i. at-

25 C 72, 150 66, 410 260 C 21,570 19,490 Flexural modulus, p.s.i. at-

25" C 2. 67 10 2 61)(106 260 C.. 1. 86 10 2 02X10 Tensile str., p.s.i.at 25 C. 52, 390 50, 690 Compressive str., p.s.i. at 25 C 43, 400 39,850 Dielectric constant, 25 C.:

10a c.p.s.:

Dry 4. 27 4. 47 Wet 4. 32 4. 55 10a c.p.s.

Dry 4. 22 4. 37 Wet 4. 26 4. 42 Dissipatiou factor, 25 C..

3 c.p.s.:

lEXAMPLE 6 A copper clad laminate was prepared as follows using theimpregnated glass cloth prepared in 'Example 5, Copper foil, weighing 1ounce per square foot, was roller covered with a 10% solution ofpolyphenylene ether polymer, Noryl type, in trichloroethylene. Thetreated copper foil Was baked at C. for 15 minutes to remove solventVand then placed, treated side down, on 6 plies of the impregnated glasscloth of Example 5 to form a l/l thick laminate on curing. The laminatewas 13 cured 30 minutes at 160 C. at 200 p.s.i. A comparison laminateWas prepared as described labove using the comparison prepreg glasscloth prepared in Example 5. Treated copper foil was prepared as aboveand laminated to the impregnated glass cloth used in preparing thecomparison example of Example 5, cured as described above. The peelstrength of the copper applied to the comparison example was 9-10 poundsper inch of Width. The comparison example was doated, copper side down,on a solder bath at 260 C. and blistering within the laminate occurredin 30-40 seconds. The copper clad laminate of this invention exhibited apeel strength of 16 pounds per inch of Width, and withstood the hotsolder float test for 40-'60 seconds before blistering. The peelstrength and solder resistance tests were run according to 'NEMA(National Electrical Manufacturers Association) lStandards PublicationfNo. LI-l-1966, for i-l0 type copper clad laminates.

EXAMPLE 7 The effect of various catalysts upon the curing and propertiesof cured or thermoset compositions were studied. The moldingcompositions were prepared as described in Example 1 and the details ofthe compositions and catalysts used are set forth in Table VI along withthe physical properties of the molded compositions. All samples weremolded for 30 minutes at 150 C. at 200 p.s.i.

TABLE VIL-MOLDED DIALLYL PHTHALATE-POLY JIEvlILELNEIENE ETHER POLYMERWITH MINERAL Diallyl phthalate:

Prepolymer 55 55 55 55 Monomer 15 15 15 Polyphenylene ether polymer. 3030 30 30 Dicumyl peroxide 2 2 2 2 Asbestos- 100 glollastonite ayloSilica.

Deflection OC 156 Hardness, M. 107 Compressive, p 17, 340 16, 900 23,370 Flexnral, p.s.i 14, 970 8, 170 12, 190 Flex. modulusXlOrB, p.s.i 1.09 1. 53 97 Specific gravity 1.698 1 640 1. 63 15 Water absorption,percent 14. 27 14 D.C., 10a/105:

Dry 4.19/4.06 4. 89/4. 37 367/357 Wet e. 25/4. 10 5. 4.2/4. 56 3. 71/3.62 D.F., 10a/106, percent:

Dry 1. 16/. 572 4.55/1. 05 1. 011/. 472 L18/.638 6.31/1. 86 1. 11/. 51020 Vol. resist.,X1015, ohm-em 3.42 0.69 7.38 Surf. resist.,X10\5, ohm--12. 9 5. 25 6. 85 Izod, it. lbs./in. notch 31 .36 .30 35 TABLE VI.MOLDEDDIALLYL PHTHALATE-(TXXXHIISYLENE ETHER COMPOSITION-EFFECT OFPolyphenylene ether polymer Diallyl orthophthalate:

Prepolymer Monomer 70 Dicumyl peroxide 2 Tert butyl perbenzoate Benzoylperoxide Lupersol 130 Flexural str., p.s.i.

25 0---. 18,190 0 C-. 332 Plex. mod., p.s.i. at-

25 C 4.44)(105 150 C 07)(105 Izod, ft.1bs./in 6. 38 Hardness, M 109Tensile str., p.s.i 7, 550 Water absorption, percent.. i0. 34 Speeiiicgravity 1. 213 D.C. 10S/105:

Dry.. 321/317 Wet B27/3.22 3 I3. D F. 10B/10 Dry 0 585/0.850 1.280/1.0760.497/0.808 0.479/0.779 0557/0639 0481/0569 Wet 0 ESO/0.976 1291/11730525/0879 OASE/0.807 0592/0676 0.514/01522 Volume resistivity, Ohm-0m-.-8 69 1015 4.28)(1015 1 02)(101I 1.43)(1015 1.94)(10m 1.53)(101 Surfaceresistivity, ohm 8 27 l05 1.55)(1016 3.52X101 7.61)(10l5 1.08)(1010.88)(101 EXAMPLE 9 A series of glass remforced molding compounds wasprepared using both short and long glass bers. The moldmg compoundscontalned 50% by Weight glass bers EXAMPLE 8 A series of mineral filledmolding compounds was prepared using inert mineral illers. The moldingcompounds contained 50% by weight Tiller and 50% by Weight of a polymermixture containing diallyl phthalate monomer, diallyl phthalateprepolymer and polyphenylene ether polymer.

The ller and polymer mixture was mixed together in a heavy duty mixerwith sufiicient solvent to wet-out the mixture. The wet mixture was rollmilled at about 90 C. to remove solvent. The dry roll milled sheet wasgranulated into a molding compound which molded easily at 150 C. 'and1500 p.s.i, in a compression mold. These compounds also transfer moldedeasily; at 150 C. and 12 tons pressure on a 2 inch diameter ram thecompound slowed 15-30 inches flow in a standard spiral test mold.Composition details of the molding compounds and physical properties ofcompression molded test pieces made from the molding compounds arecontained in Table VII.

and 50% by Weight of a polymer mixture containing diallyl phthalatemonomer, diallyl phthalate prepolymer and polyphenylene ether polymer..

The 1A inch glass fibers and polymer mixture were mixed together in aheavy duty mixer with suicient solvent to Wet-out the mixture. The wetmixture was spread out and dried to remove solvent. The dry moldingcompound (Type GDI-30 Mil-M-l9l833) Was broken into pieces which moldedeasily at C. and 1500 p.s.i. in a compression mold. These compounds alsotransfer molded easily; at C. and l2 tons ram pressure on a 2 inchdiameter ram the compounds owed 6` to l2 inches in a standard spiraltest mold. To make a short glass molding compound, Type SDG Ml-M-MF, thelong glass composition was milled on a heated two roll rubber mill toform a sheet. The sheet was cooled and ground to a molding powder.

Composition details of the molding compounds and physical properties ofcompression molded test pieces made from these compounds are containedin Table V111.

TABLE VIII.MOLDED DIALLYL PHTHALATE-POLYPHENYLENE ETHER POLYMER WITHGLASS FIBER FILLERS Comparison 9-1 9-2 9-3 9-4 Diallyl phthalate:

MOI10mer 2.5 4.9 5.1 4.9 10.5 Prepolymer 97. 5 65. 1 70.0 65. 1 59. 5Polyphenylene ether polymer 30 15 30 30 Glass bers:

v 100 Dicumyl peroxide. 2.0 2. 0 2. 0 2. 0 2. 0 Deflection, 0---. 165168 147 154 200 Hardness, M 115 112 100 106 110 Compressive p.s. 28, 86023, 730 20, 520 Flexural, p.s.l 13, 450 16, 190 1l, 680 15, 660 15, 890Flex. modulus, X104, p.S.l 1. 67 11. 9 1. 23 1. 51 1. 58 Speeiegravity 1. 700 1. 649 1. 775 1. 720 1. 713 Wt. lpsaeroent) 96 hrs. at 0.54 0. 58 0.44

e. Water absorptlon,. l 0. 18 0. 24 0. 25 0. 12 0. 6 D.C. 10H/106:

591/. 700 632/. 580 915/562 547/. 546 612/. 738 657/. 648 920/. 724764/. 591 Vol. resi 12. 9. 45 10. 4 7.03 Surf. resist., X-15, ohm.-.8.18 4. 85 4. 85 4. 32 Izod, t.1bs./in. notch 0. 47 68 54 62 EXAM-PLE 10night and 5 40 grams of this mixture was added to the A series of glassreinforced molding compounds were prepared in which the diallylicphthalate was diallyl isophthalate prepolymer and monomer. The compoundscontained 50% rby Weight glass fibers and 50% by weight of a polymermixture containing diallyl isophthalate monomer, diallyl isophthalateprepolymer and polyphenylene ether polymer.

The glass bers and polymer mixture were mixed together in a heavy dutymixer with sufficient solvent to Wet-out the mixture. The wet mixturewas spread out and dried to remove solvent. The dry molding compound,Type GDI-30, was broken into pieces which molded easily at 150 C. and1500 p.s.i. in a compression mold.

Composition details of the molding compounds and physical properties ofcompression molded test pieces made from these compounds are containedin Table IX.

Short glass molding compound, type SDG, was made from this compositionusing the procedure of Example 9.

following ingredients in a sigma mixer at C.

Grams Diallyl isophthalate prepolymer 225 Diallyl isophthalate monomerDicumyl peroxide 20 t-Butyl perbenzoate 15Vinyltris(2methoxyethoxy)silane 5 Zinc stearate 10 Wollastonite mineralfiller 400 Acetone 1500 After the ingredients were thoroughly wetter bythe acetone, 400 grams of Dacron staple ber (oc) was added to the mixer,and mixing was continued until the mixture became dry enough to formlumps. The mixed compound was then removed from the mixer and allowed todry in trays at room temperature.

This compound was used in lump form to mold a full reversal copy of anengraved printing plate and the lump form compound was preformed into asmooth sheet and TABLE IX.-MOLDED DIALLYL ISOPHTHALATE-POLYPHENYLENEETHER POLYMER WITH FIBER GLASS FILLERS Comparison 10-1 10-2 10-3 Diallylisophthalate:

Prepolymer 94 85 85 80 Monomer 5 5 5 5 Polyphenylene ether polymer. 0 2015 15 Dicumyl peroxide 2 2 2 2 Glass bers:

SD G 100 100 100 GDI 30 Deflection, OC 265 239 270 Hardness, M.-- 119111 113 Compressive, p.s.1 24, 250 23, 880 22, 990 Flexural, p.s.i 10,490 9, 480 13, 090 Flex. modulus, X10-0, p.S. l. 56 1. 22 1. 42 Specificgravity 1 690 1. 629 1. 736 Wt. loss (percent) 96 hrs. at 180 C 0. 590.56 Water absorption, percent 0.16 0. 22 0.18 D.C., 10S/10:

Dry 4. 31/4. 19 4. 03/3. 96 4.16/4. 02 4. 08/3. 98 Wet 4. 35/4. 24 4.12/4. 01 4. 25/4. 04 4. 65/4. 06 D.F., 10S/103, percent Dry .634/. 619686/. 513 579/. 483 971/. 580 Wet 719/. 650 758/. 583 769/. 553 1. 07/1.l1 Vol. resist., )(1015, ohm-cm. 4. 60 6.18 4. 51 1. 51 Surf. resist.,X1015, ohm 7. 90 6. 93 8. 04 3. 45 Izod, it.1bs./in. notch.-- 0. 45 7171 l. 35

EXAMPLE 11 pressed against an engraved printing plate at a relativelyPrinting plate example A molding compound containing primarily mineralller, synthetic organic bers, diallyl isophthalate monomer, diallylisophthalate polymer and polyphenylene ether poly mer was prepared foruse in making molded printing plates.

A mixture of equal parts diallyl isophthalate prepolymer low pressure toreproduce only the raised areas of the engraved plate. Molding wasperformed at a temperature of C. for 5 minutes using a pressure of 500p.s.i. for the premix lumps for full reproduction and at 100 p.s.i. forthe preformed sheet.

`Printing plates molded from the above compound demonstrated goodresistance to chipping in sharp corners and in raised dot areas andexcellent hot-strength and and polyphenylene ether polymer was ballmilled over 75 chemical resistance `when molding rubber or plastisol re1 7 productions of the plate at temperatures of 150 to 165 C.

As will be apparent to those skilled in the art, numerous modificationsand variations of the processes and products illustrated above may bemade Without departing from the spirit of the invention or the scope ofthe following claims.

What is claimed is:

1. A method of producing a copper clad laminate comprising coating acopper sheet with a thin lm of a polyphenylene oxide resin, heating thecoated copper to a temperature between 100 C.-l70 C., for from 5 to 30minutes, laminating the coated copper at a temperature of at least 80 C.to a base comprising a reinforcing material impregnated with at least20% by weight of a polymerizable mixture comprising (a) l to 45% byweight diallylic phthalate monomer,

(b) 20 to 75% by weight diallylic phthalate prepolymer,

(c) to 35% by Weight of a polyphenylene ether having a repeatingstructural unit of the formula wherein the oxygen atom of one unit isconnected to the benzene nucleus of the adjoining unit, n is a positiveinteger and is at least 100, R is a monovalent substituent selected fromthe group consisting of hydrogen, hydrocarbon radicals free of tertiarya-carbon atom, halohydrocarbon radicals having at least two carbon atomsbetween the halogen atom and the phenol nucleus and being free of atertiary a-carbon atom, hydrocarbonoxy radicals being free of a tertiarywcarbon atom, and halohydrocarbonoxy carbon atoms having at least twocarbon atoms between the halogen atom and phenol nucleus and being freeof tertiary wcarbon atoms; R' and R" are both monovalent substituentswhich are the same as R and in addition, halogen, and

(d) a free radical catalyst in sufficient amount to conlvert thepolymerizable material-polyphenylene ether mixture thermoset state atelevated temperatures and laminating the coated copper sheet to at leastone piece of the impregnated reinforcing material, at a temperature andpressure and for a time suiicient to convert the polymerizable mixtureto the thermo set state.

2. The method for producing copper clad laminates of claim 1 in whichthe diallylic phthalate monomer is selected from the group consisting ofdiallyl orthophthalate and diallyl isophthalate and the diallylicphthalate prepolymer is selected from the group consisting of diallylorthophthalate prepolymer and diallyl isophthalate prepolymer.

3. The method for producing copper clad laminates of claim 1 in whichthe reinforcing material is selected from the group consisting ofnon-woven fibrous mats, Woven fabrics and fibers.

4. A method of producing a copy of an engraved printing plate comprisingpressing a thermosetting resin composition comprising (a) 10 to 45 byweight diallylic phthalate monomer,

18 (b) 20 to 75% by weight diallylic phthalate prepolymer, (c) 15 to 35%by weight of a polyphenylene ether having a repeating structural unit ofthe formula wherein the oxygen atom of one unit is connected to thebenzene nuceus of the adjoining unit, n is a positive integer and is atleast 10, R is a monovalent substituent selected from the groupconsisting of hydrogen, hydrocarbon radicals free of tertiary otcarbonatom, halohydrocarbon radicals having at least two carbon atoms betweenthe halogen atom and the phenol nucleus and being free of a tertiary:at-carbon atom, hydrocarbonoxy radicals being free of a tertiarya-carbon atom, and halohydrocarbonoxy carbon atoms having at least twocarbon atoms between the halogen atom and phenol nucleus and being freeof tertiary wcarbon atoms, R and R are both monovalent substituentswhich are the same as R and in addition, halogen, and

(d) a free radical catalyst in sufiicient amount to convert thepolymerizable material-polyphenylene ether mixture thermoset state atelevated temperatures, against an engraved printing plate for at least 5minutes at a pressure of at least 50 p.s.i. at a temperature of at leastC.

5. The method of producing a copy of an engraved printing plateaccording to claim 4 in which the diallylic phthalate monomer isselected from the group consisting of diallyl orthophthalate and diallylisophthalate and the diallylic phthalate prepolymer is selected from thegroup consisting of diallyl orthophthalate prepolymer and diallylisophthalate prepolymer.

6. The method of producing a. copy of an engraved printing plateaccording to claim 4 further comprising up to parts by Weight, per 100parts of polyphenylene ether-diallylic phthalate mixture, of an inertmineral ller.

7. The method of producing a copy of an engraved printing plateaccording to claim 4l further comprising up to 100 parts by weight per100 parts of polyphenylene ether polymer-diallylic phthalate mixture ofan inert, synthetic brous ller.

References Cited UNITED STATES PATENTS 3,356,761 12/1967 Fox 260-8743,373,226 3/1968 Gowan 260-874 3,383,435 5/1968 Cizek 260-874 3,384,6825/1968 Erchak et al. 260-874 3,477,900 1l/1969 Soukup et al. 161--1943,556,928 l/l971 Zolg 161--186 ROBERT F. BURNETT, Primary Examiner R. A.DAWSON, Assistant Examiner U.S. C1. X.R.

UNITED S'lA''ES PATENT OFFICE CERTIFICATE 0F CRRECT [0N Patent No.3,68`Ll,616 Dated August 15, 1972 Invent0r(S) Cal L. Wright. et al It iscertified that error appears in the above-identified. patent andthatsaid Letters Patent are hereby corrected as shown below:

Column l, line 10, "June l, 1971" should read f--June 1, 1970- Column 2,line lO, "or" should read at.

Column 9, line 25, "10S/1o5 dry" should read --103/106 dry- Table Il,Column 10, line 45, "113" Should read `--1l1--.

' Column lO, line 6M, "tertiary" should read --ter'tiar.

Column ll, line 27, "tertiary" should read --ter'tiaicymn Table 1V,Column ll, line 60, "7.03 X 101" should read 7.03 X lO15--.

Continued on next page 7 FORM P04050 (10-69) UNITED STATES `PATENTOFFICE y CERTIFICATE 0F CORRECTION Patent No. 3',68Ll,6l6 l Dated Augustl5, 1972 Inventod) Carl L. Wr'lffht. et al It is certified that errorappears in the aboveeidentified patent and that said Letters Patent arehereby corrected as shown below: i

Column l2, line 68, "Example 5," should read Example 5..

` Table VI, Column lll, line 32, "2350" should read --l435C-.

Table VI, Column 13, line 33, "Plex Mod." should read --Flex Mod TableVI, Column lil, line 3M, I.92X1O" should read l.92XlO5-,

Table VIII, Column l5, line 20, "Water absorption," should Toad y--Wator' absorption,

Table VIII, column 15, 1in@ 22, ".915/562" :mould read -.915/.562. A

`UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 26811516 Dated August l5L 1972 Inventor(s) Carl L. Wright. et al t iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown belowz Table IX,Column l5, line 60, "D.F.,lO3/l03 dry" should read -D.F. .10B/l0'sdry-j.

Claim Il, Column 18, line ll, "nuceus" should read --nuolou:;-.

Signed and sealed this 17th day of September 1974.

SEAL) Attest:

M COY M. GIBSON JR. l C. MARSHALL DANN Atcztestng Officer Commissionerof Patents

